[translation] Start porting osh/word_.py to tagswitch

- And also tighten some of the static type signatures, e.g. to
  word__Compound rather than word_t.

34 compile errors left.

mycpp/cppgen_pass.py

@@ -1550,9 +1550,9 @@ def visit_import_from(self, o: 'mypy.nodes.ImportFrom') -> T:
 
           # TODO: Should these be moved to core/pylib.py or something?
           # They are varargs functions that have to be rewritten.
-          if name == 'log':
+          if name in ('log', 'p_die'):
             return  # do nothing
-          if name == 'p_die':
+          if name in ('switch', 'tagswitch'):  # mylib
             return  # do nothing
 
           if '.' in o.id:

mycpp/examples.sh

@@ -294,9 +294,10 @@ namespace arith_nt {
     $REPO_ROOT/pgen2/parse.py \
     $REPO_ROOT/oil_lang/expr_parse.py \
     $REPO_ROOT/oil_lang/expr_to_ast.py \
-    $REPO_ROOT/osh/bool_parse.py \
+    $REPO_ROOT/osh/word_.py \
     examples/$name.py
-    #$REPO_ROOT/osh/word_.py \
+
+    #$REPO_ROOT/osh/bool_parse.py \
 
   # TODO:
   # osh/word_.py needs its own case

mycpp/examples/pgen2_demo.py

@@ -90,6 +90,7 @@ def run_tests():
     f.close()
 
   ParseDemo(gr)
+  print('done')
 
 
 def run_benchmarks():